White R D, Sipes I G, Gandolfi A J, Bowden G T
Carcinogenesis. 1981;2(9):839-44. doi: 10.1093/carcin/2.9.839.
The damage to hepatic cell DNA caused by i.p. administration of 1,2-dibromoethane (EDB) was studied in male Swiss Webster mice. Three hours after treatment, hepatic nuclei were isolated and damage to DNA assessed by the alkaline elution technique. The method for isolation of the nuclei preserved the integrity of the DNA and in addition it was found that the purified nuclei could be frozen for at least 1 week with no detectable damage to the DNA. EDB administration (25-75 mg/kg) resulted in a dose-dependent increase in DNA single-strand breaks. More DNA single-strand breaks were detected when lysed nuclei were preincubated in the alkaline eluting solution prior to analysis. The presence of these alkali-labile sites suggests that the DNA strand breaks result, in part, from the lability of DNA sites alkylated by EDB. There was no evidence of EDB induced DNA-DNA cross-links or DNA-protein cross-links. The use of isolated hepatic nuclei as a sample for alkaline elution analysis may be a useful technique for studying the nature of DNA damage induced in vivo by carcinogens.
在雄性瑞士韦伯斯特小鼠中研究了腹腔注射1,2 - 二溴乙烷（EDB）对肝细胞DNA的损伤。处理后3小时，分离肝细胞核，并通过碱性洗脱技术评估DNA损伤。细胞核的分离方法保持了DNA的完整性，此外还发现纯化的细胞核可以冷冻至少1周，而DNA没有可检测到的损伤。给予EDB（25 - 75mg/kg）导致DNA单链断裂呈剂量依赖性增加。在分析之前，将裂解的细胞核在碱性洗脱溶液中预孵育时，检测到更多的DNA单链断裂。这些碱敏感位点的存在表明，DNA链断裂部分是由EDB烷基化的DNA位点的不稳定性导致的。没有证据表明EDB诱导了DNA - DNA交联或DNA - 蛋白质交联。使用分离的肝细胞核作为碱性洗脱分析的样本可能是一种研究致癌物在体内诱导的DNA损伤性质的有用技术。
